[libvirt-users] Snapshots: Where they are stored and how to use them?

Firstly I'd like to learn where a snapshot is stored once it has been made. I understand that the principle is that when changes occur in the VM, the difference is written to the snapshot, thus recording the differences between the date/time of the snapshot and the current value of the VM. Is that a correct assessment of the process? If that is indeed so, can I take regular snapshots and back then up onto external storage to provide a sort of system restore point at certain times in the past? I have scanned the server hard disks for the snapshot images after running "sudo virsh snapshot-create Windows /etc/libvirt/snapshot.xml" and the system reports a snapshot was taken, yet I cannot find any file that contains the snapshot. $ sudo virsh snapshot-list Windows Name Creation Time State ------------------------------------------------------------ Windows 2013-10-02 12:41:06 +0200 running What will happen to the snapshot if the host server is restarted? Some insight would be greatly appreciated. regards Roland